I'll throw my hat in. What about a medium body longroof?
A friend of mine just got a 68 coronet (?) station wagon and is planning on doing it up as a specialty Road Runner. The car runs and drives with old, but still serviceable white enamel exterior (from the 80s) with steel rims and poverty caps. Motor is a 360.

If you do get a falcon, or its uppity brother the Mustang/Cougar, remember that if its an inline 6 car, it can be a LOT of time and expense to convert it to a V8. Same with the Mopars. Not a big deal if you can weld and want to install a front clip anyway.

65 novas can be problematic as there are some 1 yr only parts on those.

Don't overlook some of the '73-76 cars. While not in your wheelhouse, they have MUCH better suspension systems (especially the chevelles), and they're not completely ugly (a lot of them just have the rubber pads on the chromed bumpers for example. Easy fix. Also, you don't see a lot of them so people notice. But you don't see a lot of them, trim parts and the like may be a pain to source.